Coil component and wireless power transmission device

Abstract

To provide a coil component that is damaged less at the application of external stress to a terminal electrode pattern.SOLUTION: A coil component 1 includes a base material 10 and coil patterns 100 and 200 formed on both surfaces of the base material 10. Terminal electrode patterns 101 and 102 forming both ends of the coil patterns 100 and 200 include first parts S1 formed on both surfaces of the base material 10 and connected through through-hole conductors 310 and 320 penetrating the base material 10, a second part S2 not formed on one surface of the base material 10 but formed on the other surface of the base material 10, and a third part S3 protruding from the base material 10 without being covered with the base material 10. The first part S1, the second part S2, and the third part S3 are disposed in this order to the outside in a radial direction of the coil patterns 100 and 200.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a coil component and a wireless power transmission device. [Background technology]

[0002] Patent Document 1 discloses a coil component having a structure in which coil patterns are formed on both sides of a substrate, and in this document, terminal electrode patterns that constitute both ends of the coil pattern protrude from the substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-194931 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a coil component in which damage caused when external stress is applied to a terminal electrode pattern is reduced. [Means for solving the problem]

[0005] A coil component according to one embodiment of the present disclosure comprises a substrate and a coil pattern arranged on the surface of the substrate, and terminal electrode patterns constituting both ends of the coil pattern each include a first portion arranged on both sides of the substrate and connected via a through-hole conductor penetrating the substrate, a second portion that is not arranged on one surface of the substrate but on the other surface of the substrate, and a third portion that protrudes from the substrate without being covered by the substrate in a planar view, and the first portion, second portion, and third portion are arranged in this order in a direction away from the coil axis of the coil pattern. [Effects of the Invention]

[0006] According to the present disclosure, it is possible to provide a coil component in which damage caused when external stress is applied to a terminal electrode pattern is reduced. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view showing the configuration of a coil component 1 according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a plan view for explaining the pattern shape of the first coil pattern 100, showing the state as viewed from the front surface 11 side of the substrate 10. As shown in FIG. [Figure 3] FIG. 3 is a plan view for explaining the pattern shape of the second coil pattern 200, showing the state as seen from the front surface 11 side of the substrate 10, that is, the state as seen through the substrate 10. [Figure 4] FIG. 4 is an equivalent circuit diagram of the coil device 1. As shown in FIG. [Figure 5] FIG. 5 is a schematic perspective view showing a state in which the connector member 400 is connected to the terminal electrode patterns 101 and 102. As shown in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view for explaining a first example of the structure in the vicinity of the end of the first coil pattern 100. As shown in FIG. [Figure 7] FIG. 7 is a schematic cross-sectional view for explaining a second example of the structure in the vicinity of the end of the first coil pattern 100. In FIG. [Figure 8] FIG. 8 is a block diagram of a wireless power transmission device 50 using the coil device 1. DETAILED DESCRIPTION OF THE INVENTION

[0008] Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

[0009] FIG. 1 is a schematic cross-sectional view showing the configuration of a coil component 1 according to an embodiment of the present disclosure.

[0010] As shown in FIG. 1 , a coil component 1 according to this embodiment includes a substrate 10, a first coil pattern 100 formed on a surface 11 of the substrate 10, and a second coil pattern 200 formed on a surface 12 of the substrate 10. As will be described in detail later, the inner peripheral ends of the first coil pattern 100 and the second coil pattern 200 are connected to each other via a plurality of through-hole conductors (only through-hole conductors 302 appear in the cross section shown in FIG. 1 ) that penetrate the substrate 10. The surface 12 of the substrate 10 is covered with a magnetic layer 20 via the second coil pattern 200. An insulating member 30 that bonds the magnetic layer 20 and the second coil pattern 200 is provided between them. That is, the insulating member 30 is provided between the magnetic layer 20 and the surface 12 of the substrate 10. An insulating member 40 is provided on the surface of the magnetic layer 20 opposite to the surface on which the insulating member 30 is provided.

[0011] The coil component 1 according to this embodiment can be used as a power transmitting coil of a wireless power transmission device. In this case, the surface 11 of the substrate 10 and the power receiving coil are disposed so as to face each other.

[0012] The material of the substrate 10 is not particularly limited, but a transparent or translucent flexible insulating material such as PET resin can be used. The substrate 10 may also be a flexible substrate made of glass cloth impregnated with epoxy resin.

[0013] FIG. 2 is a plan view for explaining the pattern shape of the first coil pattern 100, showing the state as viewed from the front surface 11 side of the substrate 10. As shown in FIG.

[0014] The first coil pattern 100 is a six-turn configuration consisting of turns 110, 120, 130, 140, 150, and 160, with turn 110 located on the outermost periphery and turn 160 located on the innermost periphery. Of these, turns 110, 120, 130, 140, and 150 are radially divided into four by three spiral slits. Meanwhile, turn 160 is radially divided into two by one spiral slit. As a result, turn 110 is divided into four lines 111-114, turn 120 is divided into four lines 121-124, turn 130 is divided into four lines 131-134, turn 140 is divided into four lines 141-144, turn 150 is divided into four lines 151-154, and turn 160 is divided into two lines 161 and 162.

[0015] Lines 111, 121, 131, 141, 151, and 161 are continuous lines wound in a spiral for six turns, and are located at the outermost periphery of each turn. Lines 112, 122, 132, 142, 152, and 162 are continuous lines wound in a spiral for six turns, and are located at the second outermost periphery of each turn. Lines 113, 123, 133, 143, and 153 are continuous lines wound in a spiral for five turns, and are located at the second innermost periphery of each turn. Lines 114, 124, 134, 144, and 154 are continuous lines wound in a spiral for five turns, and are located at the innermost periphery of each turn.

[0016] The outer peripheral ends of the lines 111 to 114 are commonly connected to the terminal electrode pattern 101. Meanwhile, the inner peripheral ends of the lines 161, 162, 153, and 154 are respectively connected to through-hole conductors 301 to 304 provided to penetrate the substrate 10. Furthermore, a terminal electrode pattern 102 is also formed on the surface 11 of the substrate 10 in addition to the coil pattern 100. Portions of the terminal electrode patterns 101 and 102 protrude from the edge 13 of the substrate 10. The tip of the terminal electrode pattern 101 is divided into two divided patterns 101a and 101b, and the tip of the terminal electrode pattern 102 is divided into two divided patterns 102a and 102b. This allows two connector pins (described later) to be connected to each of the terminal electrode patterns 101 and 102, thereby dispersing external stress applied via the connector pins. Here, the branching points where the terminal electrode patterns 101 and 102 are divided are located on the surface 11 of the substrate 10. Therefore, divided patterns 101a, 101b, 102a, and 102b have portions provided on surface 11 of base material 10 and portions protruding from base material 10. Furthermore, width W1 of divided patterns 101a, 101b, 102a, and 102b is wider than space W2 between divided patterns 101a, 101b, 102a, and 102b. This increases the mechanical strength of divided patterns 101a, 101b, 102a, and 102b and the bonding strength with connector pins, as well as the allowable current value.

[0017] FIG. 3 is a plan view for explaining the pattern shape of the second coil pattern 200, showing the state as seen from the front surface 11 side of the substrate 10, that is, the state as seen through the substrate 10.

[0018] As shown in Fig. 3, the pattern shape of the main portion of the second coil pattern 200 is the same as the pattern shape of the main portion of the first coil pattern 100. The second coil pattern 200 is a six-turn configuration consisting of turns 210, 220, 230, 240, 250, and 260, with turn 210 located on the outermost periphery and turn 260 located on the innermost periphery. Of these, turns 210, 220, 230, 240, and 250 are divided radially into four by three spiral slits. Meanwhile, turn 260 is divided radially into two by one spiral slit. As a result, turn 210 is divided into four parts into lines 211 to 214, turn 220 is divided into four parts into lines 221 to 224, turn 230 is divided into four parts into lines 231 to 234, turn 240 is divided into four parts into lines 241 to 244, turn 250 is divided into four parts into lines 251 to 254, and turn 260 is divided into two parts into lines 261 and 262.

[0019] Lines 211, 221, 231, 241, 251, and 261 are continuous lines wound spirally for six turns, and are located at the outermost periphery of each turn. Lines 212, 222, 232, 242, 252, and 262 are continuous lines wound spirally for six turns, and are located at the second outermost periphery of each turn. Lines 213, 223, 233, 243, and 253 are continuous lines wound spirally for five turns, and are located at the second innermost periphery of each turn. Lines 214, 224, 234, 244, and 254 are continuous lines wound spirally for five turns, and are located at the innermost periphery of each turn.

[0020] The outer peripheral ends of the lines 211 to 214 are connected to a common pattern 202. The common pattern 202 is connected to the terminal electrode pattern 102 via a plurality of through-hole conductors 320 provided to penetrate the substrate 10. Therefore, the common pattern 202 may also be considered to be part of the terminal electrode pattern 102. Meanwhile, the inner peripheral ends of the lines 261, 262, 253, and 254 are connected to through-hole conductors 304, 303, 302, and 301, respectively. Furthermore, a dummy pattern 201 is also formed on the front surface 12 of the substrate 10, separate from the second coil pattern 200. The dummy pattern 201 is connected to the terminal electrode pattern 101 via a plurality of through-hole conductors 310 provided to penetrate the substrate 10. Therefore, the dummy pattern 201 may also be considered to be part of the terminal electrode pattern 101. In this way, the terminal electrode pattern 101 provided on the surface 11 of the substrate 10 is connected to the dummy pattern 201 formed on the surface 12 of the substrate 10 via the plurality of through-hole conductors 310, so that the terminal electrode pattern 101 is more firmly fixed to the surface 11 of the substrate 10 and is less likely to peel off. Furthermore, the plurality of through-hole conductors 310, 320 are arranged at an angle with respect to the edge 13 of the substrate 10. As a result, even if external stress is applied to the terminal electrode patterns 101, 102, the stress applied to the through-hole conductors 310, 320 is dispersed.

[0021] FIG. 4 is an equivalent circuit diagram of the coil device 1 according to the present embodiment.

[0022] 4, a six-turn line group A1 consisting of lines 111, 121, 131, 141, 151, and 161 and a five-turn line group B4 consisting of lines 214, 224, 234, 244, and 254 are connected in series via through-hole conductor 301 to form a continuous line with a total of 11 turns. A six-turn line group A2 consisting of lines 112, 122, 132, 142, 152, and 162 and a five-turn line group B3 consisting of lines 213, 223, 233, 243, and 253 are connected in series via through-hole conductor 302 to form a continuous line with a total of 11 turns. A five-turn line group A3 consisting of lines 113, 123, 133, 143, and 153 and a six-turn line group B2 consisting of lines 212, 222, 232, 242, 252, and 262 are connected in series via through-hole conductor 303 to form a continuous line with a total of 11 turns. A five-turn line group A4 consisting of lines 114, 124, 134, 144, and 154 and a six-turn line group B1 consisting of lines 211, 221, 231, 241, 251, and 261 are connected in series via through-hole conductor 304 to form a continuous line with a total of 11 turns.

[0023] As a result, four 11-turn lines are connected in parallel between the terminal electrode patterns 101, 102 that form both ends of the first and second coil patterns 100, 200. As a result, the density distribution of the current flowing through the first and second coil patterns 100, 200 is uniform, thereby reducing DC resistance and AC resistance. Moreover, in this embodiment, the outermost line group A1 is connected to the innermost line group B4, the second outermost line group A2 is connected to the second innermost line group B3, the second innermost line group A3 is connected to the second outermost line group B2, and the innermost line group A4 is connected to the outermost line group B1. As a result, the difference between the inner and outer circumferences of the first coil pattern 100 and the second coil pattern 200 is canceled out, thereby further reducing DC resistance and AC resistance. Furthermore, since the line groups A1, A2, B1, and B2 are configured with six turns and the line groups A3, A4, B3, and B4 are configured with five turns, the total number of turns can be an odd number even though the pattern shapes of the main parts of the first and second coil patterns 100 and 200 formed on the front and back of the substrate 10 are identical to each other.

[0024] FIG. 5 is a schematic perspective view showing a state in which the connector member 400 is connected to the terminal electrode patterns 101 and 102. As shown in FIG.

[0025] As shown in FIG. 5, the connector member 400 has four connector pins 401 to 404 and a resin case 405 into which the connector pins 401 to 404 are inserted. The connector pins 401 to 404 are connected to the divided patterns 101a, 101b, 102a, and 102b that constitute the terminal electrode patterns 101 and 102, respectively. The connector pins 401 to 404 are rod-shaped bodies made of a metal such as copper, and are bent at 90 degrees. The connector pins 401 to 404 are joined to the divided patterns 101a, 101b, 102a, and 102b, respectively, by ultrasonic bonding or a similar method. In this embodiment, the connector pins 401 to 404 are joined to the surfaces (lower surfaces) of the divided patterns 101a, 101b, 102a, and 102b that come into contact with the substrate 10, and therefore the connector pins 401 to 404 do not protrude toward the surface 11 of the substrate 10. This prevents interference between the power receiving coil arranged on the front surface 11 side of the substrate 10 and the connector pins 401 to 404, thereby enabling the distance between the first and second coil patterns 100, 200 and the power receiving coil to be shortened.

[0026] Use of such a connector member 400 facilitates connection between the coil component 1 according to this embodiment and a device (such as a switching power supply circuit) in which the coil component 1 is mounted. On the other hand, when external stress is applied to the connector member 400, the stress is applied to the coil component 1 via the connector pins 401 to 404, which may result in damage to the coil component 1. However, as will be explained below, the coil component 1 according to this embodiment has a structure that makes it difficult for such external stress to concentrate in a specific location.

[0027] FIG. 6 is a schematic cross-sectional view for explaining a first example of the structure in the vicinity of the end of the first coil pattern 100. As shown in FIG.

[0028] 6, the end of the first coil pattern 100 includes a first portion S1 consisting of the terminal electrode pattern 101 and the dummy pattern 201 connected to each other via the through-hole conductor 310, a second portion S2 of the terminal electrode pattern 101 that does not overlap with the dummy pattern 201, and a third portion S3 that protrudes from the substrate 10 without being covered by the substrate 10 in a plan view. That is, the first portion S1 is a portion formed on both sides of the substrate 10, the second portion S2 is a portion formed on the other surface 11 of the substrate 10 without being formed on one surface 12 of the substrate 10, and the third portion S3 is a portion that does not overlap with the substrate 10. Here, the first portion S1, the second portion S2, and the third portion S3 are arranged in this order in a direction away from the coil axis of the first coil pattern 100. In other words, the first portion S1, the second portion S2, and the third portion S3 are arranged in this order in a direction radially outward of the first coil pattern 100. That is, the second portion S2 is located between the first portion S1 and the third portion S3. The connector pin 401 is joined to the third portion S3. By joining the connector pin 401 to the third portion S3 that does not overlap with the base material 10 in this way, the joining strength can be increased compared to joining to a portion that overlaps with the base material 10.

[0029] Here, the mechanical strength of the coil device 1 is stronger in thicker portions and weaker in thinner portions. Therefore, when external stress is applied via the connector pin 401, stress concentrates at the boundary between the thin and thick portions, making this portion more susceptible to breakage. However, in the coil device 1 according to this embodiment, the third portion S3, which is the thinnest, is located on the outermost side, the second portion S2, which is thicker than the third portion S3, is located inside the third portion S3, and the first portion S1, which is thicker than the second portion S2, is located inside the second portion S2. Therefore, stress is distributed to the boundaries C1 and C2. Here, the boundary C1 is the boundary between the first portion S1 and the second portion S2, and the boundary C2 is the boundary between the second portion S2 and the third portion S3. The boundary C2 coincides with the edge 13 of the substrate 10.

[0030] 6, edge D1 of the magnetic layer 20 overlaps with third portion S3. The insulating members 30 and 40 cover the entire surfaces of the magnetic layer 20, and their edges C2 overlap with third portion S3. By positioning edge D1 of the magnetic layer 20 and edge D2 of the insulating members 30 and 40 at positions different from boundary C2, stress applied to boundary C2 can be further alleviated. Furthermore, by positioning edge D2 of the insulating members 30 and 40 at positions different from edge D1 of the magnetic layer 20, stress can be further alleviated.

[0031] FIG. 7 is a schematic cross-sectional view for explaining a second example of the structure in the vicinity of the end of the first coil pattern 100. In FIG.

[0032] 7, the edge D1 of the magnetic layer 20 and the edge D2 of the insulating members 30 and 40 overlap with the second portion S2. Even in this case, the positions of the edges D1 and D2 are different from the position of the boundary C2, so that the stress applied to the boundary C2 can be further alleviated.

[0033] The portions connected to the other connector pins 402 to 404 also have the same structure as that shown in FIG. 6 or FIG.

[0034] As described above, in the coil device 1 according to this embodiment, the first portion S1, the second portion S2, and the third portion S3 are arranged outward in this order, which reduces damage when external stress is applied to the terminal electrode patterns 101 and 102. The external stress applied to the terminal electrode patterns 101 and 102 is also applied to the through-hole conductors 310 and 320, but because the through-hole conductors 310 and 320 are arranged at an angle with respect to the edge 13 of the substrate 10, the stress applied to the through-hole conductors 310 and 320 is also dispersed.

[0035] FIG. 8 is a block diagram of a wireless power transmission device 50 using the coil component 1 according to this embodiment.

[0036] 8 includes a coil component 1 constituting a power transmission coil, and a power transmission circuit 51 connected to the coil component 1. The power transmission circuit 51 is connected to a control circuit 52. This allows power supplied by a power source 53 to be transmitted wirelessly via the coil component 1, which is a power transmission coil for wireless power transmission.

[0037] While the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present disclosure, and it goes without saying that these modifications are also included within the scope of the present disclosure. For example, the technology according to the present disclosure may be applied to an antenna coil used in NFC (near field communication).

[0038] The technology according to the present disclosure includes, but is not limited to, the following configuration examples.

[0039] A coil component according to the present disclosure includes a substrate and a coil pattern disposed on a surface of the substrate, and terminal electrode patterns constituting both ends of the coil pattern include a first portion disposed on both surfaces of the substrate and connected via through-hole conductors penetrating the substrate, a second portion disposed on one surface of the substrate but not on the other surface of the substrate, and a third portion protruding from the substrate without being covered by the substrate in a plan view, the first portion, second portion, and third portion being disposed in this order in a direction away from the coil axis of the coil pattern. This allows external stress applied to the third portion to be dispersed to the boundary between the third portion and the second portion and the boundary between the second portion and the first portion, thereby reducing damage caused by external stress applied to the terminal electrode pattern.

[0040] The coil component according to the present disclosure may further include a connector pin joined to the third portion, which facilitates connection of the coil component to an external device.

[0041] The connector pins may be bonded to the surface of the terminal electrode pattern that comes into contact with the substrate, so that the connector pins do not protrude from the other surface of the substrate, thereby shortening the distance to the device placed on the other surface of the substrate.

[0042] The third portion may be divided into a plurality of divided patterns, which allows for dispersion of external stress applied to the terminal electrode pattern.

[0043] The pattern width of the divided patterns may be wider than the space between the divided patterns, which increases the strength of the divided patterns and also increases the allowable current value.

[0044] The second portion may be divided into a plurality of divided patterns, which allows for dispersion of external stress applied to the terminal electrode pattern.

[0045] A plurality of through-hole conductors may be provided at each end of the coil pattern, and the plurality of through-hole conductors may be arranged at an angle with respect to the edge of the substrate located at the boundary between the second and third portions, thereby dispersing stress acting on the plurality of through-hole conductors.

[0046] The coil component according to the present disclosure further includes a magnetic layer covering one surface of the substrate, and the edge of the magnetic layer may be located at a position different from the edge of the substrate and overlapping with the second or third portion, thereby increasing the inductance of the coil pattern and further dispersing external stress applied to the terminal electrode pattern.

[0047] The coil component according to the present disclosure further includes an insulating member located between the substrate and the magnetic layer, and the edges of the insulating member may be located at positions different from the edges of the substrate and the magnetic layer, thereby enabling external stress applied to the terminal electrode pattern to be more effectively dispersed.

[0048] A wireless power transmission device according to the present disclosure includes the above-described coil component and a power transmission circuit connected to a coil pattern, thereby providing a wireless power transmission device including a coil component that is less susceptible to damage when external stress is applied to the terminal electrode pattern. [Explanation of symbols]

[0049] 1 Coil parts 10 Base material 11,12 Surface of the substrate 13 Edge of substrate 20 Magnetic layer 30,40 Insulating member 40 Insulating material 50 Wireless power transmission device 51 Power transmission circuit 52 Control circuit 53 Power supply 100,200 coil patterns 101,102 Terminal electrode pattern 101a, 101b, 102a, 102b division patterns 110,120,130,140,150,160,210,220,230,240,250,260 turns 111~114, 121~124, 131~134, 141~144, 151~154, 161, 162, 211~214, 221~224, 231~234, 241~244, 251~254, 261, 262 Lines 201 Dummy Pattern 202 Common Patterns 301~304 Through-hole conductors 400 Connector parts 401~404 Connector pins 405 Resin Case A1~A4, B1~B4 line group C1,C2 boundary D1,D2 edges

Claims

1. A substrate; a coil pattern disposed on a surface of the substrate; terminal electrode patterns constituting both ends of the coil pattern each include a first portion disposed on both surfaces of the substrate and connected via a through-hole conductor penetrating the substrate, a second portion disposed on one surface of the substrate but on the other surface of the substrate, and a third portion protruding from the substrate without being covered by the substrate in a plan view; the first portion, the second portion, and the third portion are arranged in this order in a direction away from the coil axis of the coil pattern, a plurality of through-hole conductors are provided at both ends of the coil pattern, A coil component, wherein the plurality of through-hole conductors are arranged at an angle with respect to an edge of the substrate located at the boundary between the second portion and the third portion.

2. The coil component according to claim 1 , further comprising a connector pin joined to the third portion.

3. The coil component according to claim 2 , wherein the connector pin is joined to a surface of the terminal electrode pattern that is in contact with the substrate.

4. The coil component according to claim 1 , wherein the third portion is divided into a plurality of divided patterns.

5. The coil component according to claim 4 , wherein a pattern width of the divided patterns is wider than a space between the divided patterns.

6. The coil component according to claim 4 , wherein the second portion is divided into a plurality of divided patterns.

7. A substrate, a coil pattern disposed on a surface of the substrate; terminal electrode patterns constituting both ends of the coil pattern each include a first portion disposed on both surfaces of the substrate and connected via a through-hole conductor penetrating the substrate, a second portion disposed on one surface of the substrate but on the other surface of the substrate, and a third portion protruding from the substrate without being covered by the substrate in a plan view; the first portion, the second portion, and the third portion are arranged in this order in a direction away from the coil axis of the coil pattern, a magnetic layer covering the one surface of the substrate; A coil component, wherein an edge of the magnetic layer is located at a position different from an edge of the substrate and at a portion overlapping with the second or third portion.

8. further comprising an insulating member located between the substrate and the magnetic layer, The coil component according to claim 7 , wherein an edge of the insulating member is located at a position different from an edge of the substrate and an edge of the magnetic layer.

9. The coil component according to any one of claims 1 to 8, a power transmission circuit connected to the coil pattern.

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